Rudder reflex developer



P 1942- w. 1. FERNALD 2,295,836

RUDDER REFLEX DEVELOPER Filed Nov. 4, 1941 Patented Sept. 15, 1942 2,295,836 RUDDER REFLEX DEVELOPER William I. Fernald, Glendale, Califi, assignor to Corliss C. Moseley, Beverly Hills, Calif.

Application November 4, 1941, Serial No. 417,802

4 Claims.

This invention relates to machines for training airplane pilots on the ground.

An object of the invention is to provide a particularly simple and inexpensive machine for developing in a student pilot natural or instinctive steering ability.

Airplane controls are so constructed that the rudder bar is turned in the opposite direction to that in which the airplane is to be deflected. Thus, a pilot presses with his right foot to turn the plane to the right. This is in contrast to most foot steered devices, such as bob sleds, in which one presses with the right foot to turn to the left and vice versa.

Numerous machines have been developed for training pilots on the ground and various rather complicated structures have been devised for causing a dirigible seat, containing the pilot, to rotate to the right in response to application of right rudder, and to the left in response to application of left rudder. The present invention differs essentially from such other machines for the same purpose in that it is extremely simple and inexpensive while at the same time producing a very realistic simulation of the rudder response of an actual airplane.

The invention will be explained by describing in detail a particular embodiment thereof as disclosed in the drawing, in which:

Fig. 1 is a side elevation of a pilot training device in accordance with the invention;

Fig. 2 is a vertical section taken along the broken line IIII of Figure 1;

Fig. 3 is a detail section in the plane III--III of Figure 1, and

Figs. 4, and 6, are schematic diagrams illustrating the operation of the machine.

Referring to Figure 1, there is shown a stationary base I on which the movable part of the device is supported. This base I has a sloping top wall 2 to which there is bolted a bearing member 3 having a socket 4 (Fig. 2) which rotatably receives a tapered spindle 5. The spindle 5 is clamped to a longitudinally extending beam 6. Thus the spindle 5 may have formed integrally therewith a supporting plate 1 to which the beam 6 is clamped by yokes 8. A wedge member 9 may be inserted between the plate I and the beam 6 to elevate the forward end of the beam.

The beam supports a bucket seat l0 near its rear end and a rudder bar H adjacent the forward end. A control stick l2 may be swivel mounted at its lower end on the beam 6 intermediate the seat In and the rudder bar H. The

bucket seat It! may be secured to beam 6 by angle braces I3.

The rudder bar II is rotatably mounted on the beam 6. Thus, as shown to best advantage in Figures 2 and 3, the rudder bar includes a right pedal [4 and a left pedal I5 which are secured to the opposite ends of a pair of vertically spaced connecting members l6 and I1, respectively. The lower member it passes below the beam 6 and the upper member l1 passes above the beam. Both members are pivotally connected to the beam by a bolt l8 extending therethrough. Metal thrust plates l9 are provided on the upper and lower surfaces of the beam to contact the members I6 and i1 and I prefer to provide a resilient washer 20 between the nut 2| on bolt l8 and the upper member l1. By tightening or loosening the nut 2| the frictional resistance to rotation of the rudder bar may be varied.

To normally maintain the beam 6 in a predetermined position of orientation with respect to the base I and maintain the rudder bar H in neutral or crosswise position with respect to the beam 6, a pair of resilient tension members 22 and 23 are stretched between the base and the ends of the rudder bar. Thus the tension member 23 is connected between the right end of the rudder bar H and an eye 25 on the base I, which eye is positioned directly back of the right end of the rudder bar II when the bar and the beam are in neutral position. Similarly the tension member 22' is stretched between the left end of the rudder bar and an eye 24 on the base I, as shown schematically in Figure 4.

By virtue of the fact that the eyes 24' and 25 are spaced from the pivotal axis 21 of the beam 6, the tension members 22 and 23 yieldably retain both the beam and the rudder bar in the neutral position shown in Figure 4. This will be apparent by observing that, if the beam 6 is rotated clockwise about the axis 21, it tends to stretch the member 22 more than the member 23 and, although the rudder bar II will rotate counterclockwise on the beam 6 in response to the differential tension applied thereto by the members 22 and 23, the total tension of both members will be increased so that force is required to maintain the beam out of neutral position.

The operation of the device will be apparent from an inspection of Figures 4, 5 and 6, which indicate What happens when the pilot applies right rudder. Thus referring to Figure 5, the

application of right rudder has stretched the member 23 while relieving the tension on member 22. The force resulting from the increased tension of member 23 is applied through the leg of the pilot (as indicated schematically by the arrow 28) to the beam 6, causing the latter to rotate clockwise as shown in Figure 6. Obviously, if left rudder is applied, the rudder bar II is rocked clockwise with respect to the beam 6, thereby increasing the tension on the member 22 and causing it to swing the entire rotatable assembly in counterclockwise direction, "or

to the left.

.1. A device of the type described comprising:

The structure, therefore, always func tions rotate the beam 6 and the seat |0,,abo'ut.the'

pivotal axis 21 to the right whe'nrright'rudder" is applied and to the left when left rudder is applied. Furthermore, the response of the rotatable assembly is slow because of its inertia. The speed of response can be varied somewhat by increasing or decreasing the weight of the rotatable assembly and also by varying the strength of the resilient connecting members 22 and,'23. V

"The members 22 and 23 may be made of rubber,- preferably in the form of laminated strands, or they may be helical tension springs.

There is shown in Figure 1 a housing '30 which largely encloses the pilot and tends to simulate to the pilot the fuselage of an airplane.

It is usually desirable to provide the dummy control stick l2 and instruct the student to use it, "although it has no actual effect on the machine.

A student pilot while using the machine should keep his eyes focused on a distant object or the horizon and endeavor to swing the machine ofi neutral and then return it to neutral position with as little overswing as possible/ It is often desirable for an instructor to stand behind the machine and force it off neutral position at intervals (by pressing against the rear end of the beam 6 with his foot) and then observe how the pilot manipulates the rudder to bring the machine back to neutral. Thus assume that the instructor has swung the machine to the right intothe position shown in Fig. 6. If the student pilot's reflexes have been properly developed, he

will'immediately and instinctively apply left rudder, which'will have the desired effect of swinging the machine leftward back toward neutral position] On the'other hand, if the pilots reflexes are not properly developed his natural inclination will be to apply right rudder, which will tend to hold the machine in the deflected position of Fig. 6, or advance it still further'to the right.

The machine can be adjusted to simulate a plane'on the ground before take-off by removing the wedge 9 to bring the beam 6 parallel to the to-p'2 of the base'l and then elevating the front end of the base I to level the top 2. When a base member, a frame having a seat thereon, means rotatably'supporting said frame on said base member. pedal means including right and left pedals, means supporting said pedal means for forward and rearward movement of said pedals with respect to said frame, yieldable connecting means directly connecting said. pedal means to said base member for yieldably retaining said frame in a predetermined position of rotation with respect tosaid base and yieldably retaining said pedals in neutral position. v V

2. A device of the type descrbed comprising: a base member, a frame having a seat thereon, means rotatably supporting said frame on said base member for horizontal swinging movement, a rudder bar pivotally mounted on said frame in front of said seat, and spring means interconnecting the opposite ends of said rudder bar tofsaid base member, said spring means being connected to said base member at such points thereon that rocking movement of said frame in one direction with respect to said base and rocking movement of said rudder bar in the opposite direction with respect to said frame both distort said spring means in the same way whereby the reaction of said spring means in responseto rocking of the rudder bar tends to rock the frame in the same direction. 7

3. A device as described in claim 1, including means for adjustably frictionally resisting rotation of said rudder bar onsaid'frame.

4. A device of the typedescribed comprising:

-a base member,- affranie, and means rotatably supporting it on said base member for rotation about a vertical axis, a seat on said frame member, a rudder bar pivotally supported on said frame member-in front of said seat, and'apair of tension spring means, one connected from one end of said rudder bar to said base member and the other connected from the other end of said rudder bar to said base member, both said tension members extending rearwardly from the ends of said rudder bar substantially parallel to the vertical longitudinal plane 'of 'said frame member and being connected to said base at points rearwardly disposed from the pivotal axis of said frame member, a

WILLIAM I. FERNALD. 

